1. Field of The Invention
This invention concerns an improved stitch-bonded fabric which includes a layer of a nonwoven fabric and layers of split polymeric films held together by a stitching yarn. The invention also concerns a tufted pile fabric in which the stitch-bonded fabric is a primary backing.
2. Description of the Prior Art
Stitch-bonded fabrics made from layers of oriented synthetic organic polymer films which have been split into ribbons or filaments are known. For example, such stitch-bonded fabrics having a warp layer and two weft layers of split film elements stitched together by yarn have been used commercially, particularly in East Germany. These fabrics are made from "Florofol" film, which is an oriented film of an 80/20 blend of polyester and low-density polyethylene polymers, available from Kombination Textima of Karl Marx Stadt, East Germany. However, several problems were encountered when attempts were made to use these stitch-bonded fabrics for backings of tufted pile carpets, especially when high speed tufting and closely spaced tuft rows were employed. The tufting operation often caused breakage of the stitches of the stitching yarn and excessive fibrillation of the split film elements, to such an extent that portions of the split film elements unraveled or projected from the back surface of the tufted material. As a result, a tufted material was produced that had poorer pile uniformity, weaker tuft bind, and less stability in a bias direction than were desired.
The manner in which a multi-needle "Mali" stitching machine can be used to make the above-described stitch-bonded split-film fabric is disclosed by Ploch et al., U.S. Pat. No. 3,769,815. Ploch et al., also discloses various other stitch-bonded layered structures, though none are suggested for any purpose related to carpet backings. For example, in column 5, lines 21-31, Ploch et al., discloses a stitch-bonded layered fabric which includes two split-film weft layers separated from a split-film warp layer by a nonwoven material.
The purpose of the present invention is to provide a means for overcoming, or at least significantly reducing, the problems encountered with the known stitch-bonded split-film fabrics used for primary carpet backings.